Valve plate of reciprocating compressor

ABSTRACT

Provided is a valve plate of a reciprocating compressor, the reciprocating compressor including a front housing and a rear housing, a cylinder block having a plurality of cylinder bores, a drive shaft rotatably supported by the front housing and the cylinder block, a swash plate connected to the drive shaft to be rotated therewith to vary its inclination angle, pistons reciprocally accommodated in the cylinder bores depending on slide movement of the swash plate, a valve plate installed between one end of the cylinder block and the rear housing and having a suction port and a discharge port, and a suction chamber and a discharge chamber that are formed in the rear housing with the valve plate interposed therebetween, characterized in that an oil suction passage, an oil discharge passage and a coolant supply passage are formed in a surface of the valve plate opposite to the pistons, the oil discharge passage is constituted by at least two branch passages directed from a center part toward an outer periphery of the valve plate, and the branch passages are connected by a connecting passage at the center part. Therefore, it is possible to appropriately distribute the pressure of oil to prevent oil leakage to the coolant supply passage, etc., even when the pressure of the oil discharged through the oil discharge passage is high. Further, the branch passages and the connecting passage have a specific shape to enable smooth flow of the oil.

TECHNICAL FIELD

The present invention relates to a valve plate of a reciprocating compressor, and more particularly, to a valve plate of a reciprocating compressor capable of lowering the pressure of discharged oil to prevent leakage of the discharged oil to a coolant supply passage.

BACKGROUND ART

In general, conventional reciprocating compressors are widely used in air conditioners for automobiles, each of which commonly includes a piston, a piston driving apparatus, a cylinder block, valves, and so on.

Typical examples of the reciprocating compressors are swash plate type compressors, which have been widely used in recent times.

The swash plate type compressor is characterized in that an inclination angle of a swash plate is varied according to variation in thermal load to control a stroke of a piston to thereby accomplish precise motion control, and the inclination angle of the swash plate is continuously varied to reduce abrupt torque variation of an engine due to the compressor to thereby improve ride comfort of a vehicle even during operation of the compressor.

In the reciprocating compressor, coolant is sucked through a suction chamber to be compressed by the piston, and the compressed coolant is discharged into a discharge chamber to transmit the coolant into a cooling cycle repetitively.

The conventional swash plate type compressor generally includes a front housing and a rear housing, a cylinder block disposed between the front housing and the rear housing, a plurality of pistons reciprocating in cylinder bores of the cylinder block, a drive shaft disposed in the housing and transmitting rotation movement from an external power source to drive the pistons, a swash plate connected to the plurality of pistons and connected to the drive shaft, and a swash plate chamber for accommodating the swash plate, etc.

In addition, an oil circulation structure is employed in the compressor to circulate oil therethrough.

Further, in recent times, an oil flow groove has been formed in a surface of the valve plate opposite to the piston to circulate the oil.

However, since the conventional compressor is concentrated on only a function of circulating oil with no regard to the oil pressure, when a high pressure is applied to the oil flow groove formed in the valve plate, the oil may leak, thereby decreasing efficiency of the compressor.

In addition, a separate element for discharging the coolant remaining in the swash plate chamber is needed, which complicates the structure of the compressor.

DISCLOSURE OF INVENTION Technical Problem

In order to solve the foregoing and/or other problems, it is an object of the present invention to provide a valve plate of a reciprocating compressor capable of dividing an oil discharge passage to prevent oil leakage between a valve plate and a cylinder block even when an oil discharge pressure is high.

Technical Solution

One aspect of the present invention provides a valve plate of a reciprocating compressor, the reciprocating compressor including a front housing and a rear housing, a cylinder block having a plurality of cylinder bores, a drive shaft rotatably supported by the front housing and the cylinder block, a swash plate connected to the drive shaft to be rotated therewith to vary its inclination angle, pistons reciprocally accommodated in the cylinder bores depending on slide movement of the swash plate, a valve plate installed between one end of the cylinder block and the rear housing and having a suction port and a discharge port, and a suction chamber and a discharge chamber that are formed in the rear housing with the valve plate interposed therebetween, characterized in that an oil suction passage, an oil discharge passage and a coolant supply passage are formed in a surface of the valve plate opposite to the pistons, the oil discharge passage is constituted by at least two branch passages directed from a center part toward an outer periphery of the valve plate, and the branch passages are connected by a connecting passage at the center part.

In this case, the valve plate may have a circular shape and the branch passages may radially extend from the center part.

In addition, the connecting passage may have an arcuate shape concentric with the circular shape.

Further, the oil suction passage may extend from the center part in a direction opposite to the oil discharge passage.

Furthermore, the oil suction passage may extend in a radial direction of the circular shape.

Meanwhile, the coolant supply passage may extend from the center part toward the outer periphery of the circular shape and may have a coolant flow hole formed at an end thereof.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of a compressor employing a valve plate in accordance with an exemplary embodiment of the present invention;

FIG. 2 is a front view of the structure of the valve plate in accordance with an exemplary embodiment of the present invention; and

FIG. 3 is a perspective view of the structure of the valve plate in accordance with an exemplary embodiment of the present invention.

MODE FOR THE INVENTION

An exemplary embodiment of the present invention will now be described in detail with reference to FIGS. 1 to 3.

As shown in FIG. 1, a reciprocating compressor 1000 in accordance with the present invention includes a front housing 120 and a rear housing 130, a cylinder block 110 having a plurality of cylinder bores 110 a, a drive shaft 140 rotatably supported by the cylinder block 110, a swash plate 150 connected to the drive shaft 140 by a connecting link 600 and rotated by the drive shaft 140 to vary an inclination angle thereof, pistons 200 reciprocally accommodated in the cylinder bores 110 a depending on slide movement of the swash plate 150, a valve plate 300 installed between one end of the cylinder block 110 and the rear housing 130, and a suction chamber 131 and a discharge chamber 132 formed in the rear housing 130 with the valve plate 300 interposed therebetween.

Specifically, the front housing 120 and the rear housing 130 are installed at both sides of the cylinder block 110, and the valve plate 300 is installed between the rear housing 130 and the cylinder block 110.

In addition, the suction chamber 131 and the discharge chamber 132 are formed in the rear housing 130, and the valve plate 300 has suction ports 331 for communicating the cylinder bores 110 a with the suction chamber 131 and discharge ports 332 for communicating the cylinder bores 110 a with the discharge chamber 132.

Further, suction valves and discharge valves are respectively installed in the suction ports 331 and the discharge ports 332 that are respectively formed in the valve plate 300 to open and close the suction ports 331 and the discharge ports 332 using variation in pressure according to reciprocal movement of the pistons 200.

Furthermore, as shown in FIGS. 2 and 3, in accordance with the present exemplary embodiment, an oil suction passage 380 a, an oil discharge passage 380 b and a coolant supply passage 390 are formed in a surface of the valve plate 300 opposite to the pistons 200.

First, the oil discharge passage 380 b is constituted by at least two branch passages (a) and (b) formed from a center part 300 a toward an outer periphery of the valve plate 300, and the branch passages (a) and (b) are connected by a connecting passage (c) in the center part 300 a.

As described above, since the oil discharge passage 380 b is branched into at least two passages, an initial pressure (pressure at the connecting passage) of the oil can be appropriately distributed to be discharged at a low pressure.

Ultimately, it is possible to prevent oil leakage to peripheral parts such as the coolant supply passage 390 due to the pressure of the discharged oil.

In addition, the valve plate 300 may have a circular shape, and the branch passages (a) and (b) may radially extend from a center part of the circular shape. Therefore, the oil pressure can be evenly distributed so that the oil can flow smoothly.

Further, when the connecting passage (c) has an arcuate shape concentric with the circular shape, the oil can flow more smoothly.

Meanwhile, the oil suction passage 380 a extends from the center part 300 a of the valve plate 300 in a direction opposite to the oil discharge passage 380 b.

Specifically, the oil suction passage 380 a extends in a radial direction of the circular valve plate 300 so that the oil can be introduced more smoothly. The outer end of the oil suction passage 380 a is in communication with a control valve 800 of the rear housing 130. Therefore, when the oil separated from the coolant gas by an oil separator 700 passes through the control valve 800 to be stored in a lower part of the cylinder block 110, the oil is sucked upward through the oil suction passage 380 a by an oil pump to be distributed into the respective parts.

In addition, the coolant supply passage 390 extends from a center part toward an outer periphery of the circular valve plate 300, and has a coolant flow hole 370 formed at its end. The coolant flow hole 370 is in communication with the suction chamber 131 of the rear housing 130.

Meanwhile, the cylinder block 110 has a plurality of cylinder bores 110 a, and the coolant introduced from the suction chamber 131 by the pistons 200 reciprocating in the cylinder bores 110 a is continuously compressed.

The drive shaft 140 is rotatably supported by the front housing 120 and the cylinder block 110, and a pulley P is coupled to one end of the drive shaft 140 as a power source.

The swash plate 150 is slidably coupled to the pistons 200 via a shoe 201.

Further, the swash plate 150 is connected to the drive shaft 140 through a link mechanism.

Here, the link mechanism includes connecting projections 155 respectively formed at front and rear surfaces of the swash plate 150, and connecting links 600 connected to the connecting projections 155 and the drive shaft 140 via hinge pins at their ends.

Therefore, the connecting links 600 and the connecting projections 155 can be hinged with respect to the drive shaft 140.

Here, the oil separator 700 is installed in the discharge chamber 132 of the rear housing 130.

That is, since some oil is contained in the coolant sucked from the discharge chamber 132 of the rear housing 130, the oil can be separated by a centrifugal force through the oil separator 700 so that only pure gas coolant can be circulated through a coolant cycle.

More specifically, the oil separator 700 includes an inner recess 710 having a gas discharge port 711, an outer recess 720 formed along the peripheral of the inner recess 710 and in communication with the discharge port 332, and an oil discharge port 730 formed from the inner recess 710 and in communication with the control valve 800.

Hereinafter, operation of the valve plate in accordance with the present invention will be described in brief while describing an operation mechanism of the compressor and a flow mechanism of coolant and oil.

First, when the compressor 1000 is operated, the pulley P connected to an engine (not shown) is rotated, and the drive shaft 140 installed at the pulley P is rotated.

As the drive shaft 140 rotates, the swash plate 150 is rotated in an inclination-variable manner, and the pistons 200 are slid by the swash plate 150 to perform compression. As the pistons 200 are operated, the coolant is introduced into the suction chamber 131 of the rear housing 130 to be continuously supplied into the cylinder bores 110 a through the suction ports 331 of the valve plate 300.

Then, the coolant introduced through the suction ports 331 of the valve plate 300 is compressed in the cylinder bores 110 a by the pistons 200, and the compressed coolant is introduced into the outer recess 720 of the oil separator 700 through the discharge ports 332 of the valve plate 300.

Next, the coolant is introduced into the inner recess 710 from the outer recess 720 through a coolant introduction groove 741 formed in a guide wall to separate the oil from the coolant gas using a centrifugal force.

At this time, the oil having large density is collected in the side bottom of the inner recess 710 outside the gas discharge port 711 and then continuously directed to the control valve 800 through the oil discharge port 730.

The oil passed through the control valve 800 passes through an oil distributing hole 145 formed through the drive shaft 140 in a longitudinal direction thereof to be supplied into the swash plate chamber 120 a or peripheral parts thereof by the oil pump.

Then, the oil passed through the respective parts passes through the peripheral parts of the oil pump to be introduced into the cylinder bores 110 a via the oil discharge passage 380 b. Next, the oil is discharged to the discharge chamber 132 by operation of the pistons 200 together with the coolant.

Meanwhile, some of the coolant gas remaining in the swash plate chamber 120 a passes through a coolant suction hole 146 formed through the drive shaft 140 to be introduced into the suction chamber 131 via the coolant flow hole 370. The coolant introduced into the suction chamber 131 is mixed with the coolant introduced through the cooling cycle.

Solid arrows of FIG. 1 represent flow paths of the oil, and dotted arrows of FIG. 1 represent flow paths of the coolant.

The valve plate of a reciprocating compressor in accordance with the present invention has been exemplarily described, and the valve plate may be applied to other typical reciprocating compressors, on condition that the compressors include a housing, a swash plate, a drive shaft, pistons, cylinder bores, and so on.

INDUSTRIAL APPLICABILITY

According to a valve plate of a reciprocating compressor of the present invention, since an oil suction passage, an oil discharge passage and a coolant supply passage are formed in a surface of the valve plate opposite to pistons, the oil discharge passage is constituted by at least two branch passages formed from a center part toward an outer periphery of the valve plate, and the branch passages are connected by a connecting passage at the center part, it is possible to appropriately distribute the pressure of oil to prevent oil leakage to the coolant supply passage, etc., even when the pressure of the oil discharged through the oil discharge passage is high.

In addition, since the oil can be appropriately supplied into inner elements of the compressor, without oil leakage, it is possible to maintain the entire efficiency of the compressor.

Further, the branch passages and the connecting passage have a specific shape to enable smooth flow of the oil.

Furthermore, the oil suction passage also has a specific shape to enable smooth flow of the oil. 

1. A valve plate of a reciprocating compressor, the reciprocating compressor comprising a front housing and a rear housing, a cylinder block having a plurality of cylinder bores, a drive shaft rotatably supported by the front housing and the cylinder block, a swash plate connected to the drive shaft to be rotated therewith to vary its inclination angle, pistons reciprocally accommodated in the cylinder bores depending on slide movement of the swash plate, a valve plate installed between one end of the cylinder block and the rear housing and having a suction port and a discharge port, and a suction chamber and a discharge chamber that are formed in the rear housing with the valve plate interposed therebetween, characterized in that an oil suction passage, an oil discharge passage and a coolant supply passage are formed in a surface of the valve plate opposite to the pistons, the oil discharge passage is constituted by at least two branch passages directed from a center part toward an outer periphery of the valve plate, and the branch passages are connected by a connecting passage at the center part.
 2. The valve plate of a reciprocating compressor according to claim 1, wherein the valve plate has a circular shape and the branch passages radially extend from the center part.
 3. The valve plate of a reciprocating compressor according to claim 2, wherein the connecting passage has an arcuate shape concentric with the circular shape.
 4. The valve plate of a reciprocating compressor according to claim 2 or 3, wherein the oil suction passage extends from the center part in a direction opposite to the oil discharge passage.
 5. The valve plate of a reciprocating compressor according to claim 4, wherein the oil suction passage extends in a radial direction of the circular shape.
 6. The valve plate of a reciprocating compressor according to claim 4, wherein the coolant supply passage extends from the center part toward the outer periphery of the circular shape and has a coolant flow hole formed at an end thereof. 